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Reduced sense of smell is a common symptom in patients with chronic rhinosinusitis (CRS). Although it is often under-diagnosed by healthcare providers, reduced sense of smell can have a substantial negative impact on patient's quality of life as measured by health-related quality of life (HRQoL) assessments and patient-reported outcomes. This narrative review describes current smell loss diagnosis and management guidelines in CRS, and the relationship between smell loss and CRS. Reduced sense of smell can be an indication of CRS disease severity in patients with (CRSwNP) and without nasal polyps (CRSsNP), and recovery of smell can be an indicator of successful CRS treatment. The current first-line therapeutic options for smell loss are intranasal corticosteroids and nasal irrigation, and second-line therapeutic options include systemic steroids and surgery. Shared decision-making between patient, caregiver, and healthcare provider is important when choosing the most appropriate CRS treatment option. Emerging biologic therapies that target type 2 inflammation signaling pathways, such as dupilumab, omalizumab, and mepolizumab, have been shown to improve smell and taste in randomized controlled trials of patients with CRSwNP. A graphical abstract and video abstract are available with this article. Plain Language Summary: Chronic rhinosinusitis (CRS) is an inflammatory condition often associated with a loss of smell and taste. Patients with CRS and a loss of smell often rate their quality of life as poor and are more likely to also suffer from depression and anxiety than patients without smell loss. Patients with severe smell loss are also more likely to have increased severity of CRS disease by other measures. Standard treatments for smell loss include topical steroids, corticosteroids absorbed into the whole body system (systemic), and/or sinonasal surgery, but the effects may not last, and patients may experience side effects when they use repeated short bursts or long-term treatment with systemic corticosteroids. A newer treatment option for CRS is biologic therapy, which targets the immunologic pathways associated with inflammation. Biologic therapies have been shown to be effective in the treatment of CRS with nasal polyps including improvement in sense of smell. Here, we review the most common diagnostic tests and treatment options for CRS-associated smell loss and show how severity of smell loss is linked to severity of CRS. -o4AhrHG7BfpfqMBka8hwD Supplementary file1 (MP4 60193 kb) [ABSTRACT FROM AUTHOR]

Introduction: Stable isotope tracers have been increasingly used in preclinical cancer model systems, including cell culture and mouse xenografts, to probe the altered metabolism of a variety of cancers, such as accelerated glycolysis and glutaminolysis and generation of oncometabolites. Comparatively little has been reported on the fidelity of the different preclinical model systems in recapitulating the aberrant metabolism of tumors. Objectives: We have been developing several different experimental model systems for systems biochemistry analyses of non-small cell lung cancer (NSCLC1) using patient-derived tissues to evaluate appropriate models for metabolic and phenotypic analyses. Methods: To address the issue of fidelity, we have carried out a detailed Stable Isotope-Resolved Metabolomics study of freshly resected tissue slices, mouse patient derived xenografts (PDXs), and cells derived from a single patient using both 13C6-glucose and 13C5,15N2-glutamine tracers. Results: Although we found similar glucose metabolism in the three models, glutamine utilization was markedly higher in the isolated cell culture and in cell culture-derived xenografts compared with the primary cancer tissue or direct tissue xenografts (PDX). Conclusions: This suggests that caution is needed in interpreting cancer biochemistry using patient-derived cancer cells in vitro or in xenografts, even at very early passage, and that direct analysis of patient derived tissue slices provides the optimal model for ex vivo metabolomics. Further research is needed to determine the generality of these observations. [ABSTRACT FROM AUTHOR]

Phosphoinositide-3-kinase-γ (PI3Kγ) is implicated as a target to repolarize tumour-associated macrophages and promote antitumour immune responses in solid cancers1–4. However, cancer cell-intrinsic roles of PI3Kγ are unclear. Here, by integrating unbiased genome-wide CRISPR interference screening with functional analyses across acute leukaemias, we define a selective dependency on the PI3Kγ complex in a high-risk subset that includes myeloid, lymphoid and dendritic lineages. This dependency is characterized by innate inflammatory signalling and activation of phosphoinositide 3-kinase regulatory subunit 5 (PIK3R5), which encodes a regulatory subunit of PI3Kγ5 and stabilizes the active enzymatic complex. We identify p21 (RAC1)-activated kinase 1 (PAK1) as a noncanonical substrate of PI3Kγ that mediates this cell-intrinsic dependency and find that dephosphorylation of PAK1 by PI3Kγ inhibition impairs mitochondrial oxidative phosphorylation. Treatment with the selective PI3Kγ inhibitor eganelisib is effective in leukaemias with activated PIK3R5. In addition, the combination of eganelisib and cytarabine prolongs survival over either agent alone, even in patient-derived leukaemia xenografts with low baseline PIK3R5 expression, as residual leukaemia cells after cytarabine treatment have elevated G protein-coupled purinergic receptor activity and PAK1 phosphorylation. Together, our study reveals a targetable dependency on PI3Kγ–PAK1 signalling that is amenable to near-term evaluation in patients with acute leukaemia.Using a multimodal approach across acute leukaemias, a targetable PI3Kγ dependency in leukaemias is explored. [ABSTRACT FROM AUTHOR]

Leukemias and their bone marrow microenvironments undergo dynamic changes over the course of disease. However, little is known about the circulation kinetics of leukemia cells, nor the impact of specific factors on the clearance of circulating leukemia cells (CLCs) from the blood. To gain a basic understanding of CLC dynamics over the course of disease progression and therapeutic response, we apply a blood exchange method to mouse models of acute leukemia. We find that CLCs circulate in the blood for 1–2 orders of magnitude longer than solid tumor circulating tumor cells. We further observe that: (i) leukemia presence in the marrow can limit the clearance of CLCs in a model of acute lymphocytic leukemia (ALL), and (ii) CLCs in a model of relapsed acute myeloid leukemia (AML) can clear faster than their untreated counterparts. Our approach can also directly quantify the impact of microenvironmental factors on CLC clearance properties. For example, data from two leukemia models suggest that E-selectin, a vascular adhesion molecule, alters CLC clearance. Our research highlights that clearance rates of CLCs can vary in response to tumor and treatment status and provides a strategy for identifying basic processes and factors that govern the kinetics of circulating cells. A blood exchange system reveals that leukemia cells clear faster in the blood than circulating tumor cells from solid tumors and that clearance rates can vary in response to tumor and treatment status. [ABSTRACT FROM AUTHOR]

Myeloid derived suppressor cells (MDSCs) are key regulators of immune responses and correlate with poor outcomes in hematologic malignancies. Here, we identify that MDSC mitochondrial fitness controls the efficacy of doxorubicin chemotherapy in a preclinical lymphoma model. Mechanistically, we show that triggering STAT3 signaling via β2-adrenergic receptor (β2-AR) activation leads to improved MDSC function through metabolic reprograming, marked by sustained mitochondrial respiration and higher ATP generation which reduces AMPK signaling, altering energy metabolism. Furthermore, induced STAT3 signaling in MDSCs enhances glutamine consumption via the TCA cycle. Metabolized glutamine generates itaconate which downregulates mitochondrial reactive oxygen species via regulation of Nrf2 and the oxidative stress response, enhancing MDSC survival. Using β2-AR blockade, we target the STAT3 pathway and ATP and itaconate metabolism, disrupting ATP generation by the electron transport chain and decreasing itaconate generation causing diminished MDSC mitochondrial fitness. This disruption increases the response to doxorubicin and could be tested clinically. [ABSTRACT FROM AUTHOR]

Ultra-endurance running (UER) poses extreme mental and physical challenges that present many barriers to completion, let alone performance. Despite these challenges, participation in UER events continues to increase. With the relative paucity of research into UER training and racing compared with traditional endurance running distance (e.g., marathon), it follows that there are sizable improvements still to be made in UER if the limitations of the sport are sufficiently understood. The purpose of this review is to summarise our current understanding of the major limitations in UER. We begin with an evolutionary perspective that provides the critical background for understanding how our capacities, abilities and limitations have come to be. Although we show that humans display evolutionary adaptations that may bestow an advantage for covering large distances on a daily basis, these often far exceed the levels of our ancestors, which exposes relative limitations. From that framework, we explore the physiological and psychological systems required for running UER events. In each system, the factors that limit performance are highlighted and some guidance for practitioners and future research are shared. Examined systems include thermoregulation, oxygen delivery and utilisation, running economy and biomechanics, fatigue, the digestive system, nutritional and psychological strategies. We show that minimising the cost of running, damage to lower limb tissue and muscle fatigability may become crucial in UER events. Maintaining a sustainable core body temperature is critical to performance, and an even pacing strategy, strategic heat acclimation and individually calculated hydration all contribute to sustained performance. Gastrointestinal issues affect almost every UER participant and can be due to a variety of factors. We present nutritional strategies for different event lengths and types, such as personalised and evidence-based approaches for varying types of carbohydrate, protein and fat intake in fluid or solid form, and how to avoid flavour fatigue. Psychology plays a vital role in UER performance, and we highlight the need to be able to cope with complex situations, and that specific long and short-term goal setting improves performance. Fatigue in UER is multi-factorial, both physical and mental, and the perceived effort or level of fatigue have a major impact on the ability to continue at a given pace. Understanding the complex interplay of these limitations will help prepare UER competitors for the different scenarios they are likely to face. Therefore, this review takes an interdisciplinary approach to synthesising and illuminating limitations in UER performance to assist practitioners and scientists in making informed decisions in practice and applicable research. [ABSTRACT FROM AUTHOR]

Tumours most often arise from progression of precursor clones within a single anatomical niche. In the bone marrow, clonal progenitors can undergo malignant transformation to acute leukaemia, or differentiate into immune cells that contribute to disease pathology in peripheral tissues1–4. Outside the marrow, these clones are potentially exposed to a variety of tissue-specific mutational processes, although the consequences of this are unclear. Here we investigate the development of blastic plasmacytoid dendritic cell neoplasm (BPDCN)—an unusual form of acute leukaemia that often presents with malignant cells isolated to the skin5. Using tumour phylogenomics and single-cell transcriptomics with genotyping, we find that BPDCN arises from clonal (premalignant) haematopoietic precursors in the bone marrow. We observe that BPDCN skin tumours first develop at sun-exposed anatomical sites and are distinguished by clonally expanded mutations induced by ultraviolet (UV) radiation. A reconstruction of tumour phylogenies reveals that UV damage can precede the acquisition of alterations associated with malignant transformation, implicating sun exposure of plasmacytoid dendritic cells or committed precursors during BPDCN pathogenesis. Functionally, we find that loss-of-function mutations in Tet2, the most common premalignant alteration in BPDCN, confer resistance to UV-induced cell death in plasmacytoid, but not conventional, dendritic cells, suggesting a context-dependent tumour-suppressive role for TET2. These findings demonstrate how tissue-specific environmental exposures at distant anatomical sites can shape the evolution of premalignant clones to disseminated cancer.Blastic plasmacytoid dendritic cell neoplasm (BPDCN) arises from clonal (premalignant) haematopoietic precursors in the bone marrow, and BPDCN skin tumours first develop at sun-exposed anatomical sites and are distinguished by clonally expanded mutations induced by ultraviolet radiation. [ABSTRACT FROM AUTHOR]

Single cell metabolomics is an emerging and rapidly developing field that complements developments in single cell analysis by genomics and proteomics. Major goals include mapping and quantifying the metabolome in sufficient detail to provide useful information about cellular function in highly heterogeneous systems such as tissue, ultimately with spatial resolution at the individual cell level. The chemical diversity and dynamic range of metabolites poses particular challenges for detection, identification and quantification. In this review we discuss both significant technical issues of measurement and interpretation, and progress toward addressing them, with recent examples from diverse biological systems. We provide a framework for further directions aimed at improving workflow and robustness so that such analyses may become commonly applied, especially in combination with metabolic imaging and single cell transcriptomics and proteomics. [ABSTRACT FROM AUTHOR]

The combination of single-cell transcriptomics with mitochondrial DNA variant detection can be used to establish lineage relationships in primary human cells, but current methods are not scalable to interrogate complex tissues. Here, we combine common 3′ single-cell RNA-sequencing protocols with mitochondrial transcriptome enrichment to increase coverage by more than 50-fold, enabling high-confidence mutation detection. The method successfully identifies skewed immune-cell expansions in primary human clonal hematopoiesis. Clonal dynamics are inferred from mitochondrial variants in primary human cells. [ABSTRACT FROM AUTHOR]

Although the principles behind assessment for and as learning are well-established, there can be a struggle when reforming traditional assessment of learning to a program which encompasses assessment for and as learning. When introducing and reporting reforms, tensions in faculty may arise because of differing beliefs about the relationship between assessment and learning and the rules for the validity of assessments. Traditional systems of assessment of learning privilege objective, structured quantification of learners' performances, and are done to the students. Newer systems of assessment promote assessment for learning, emphasise subjectivity, collate data from multiple sources, emphasise narrative-rich feedback to promote learner agency, and are done with the students. This contrast has implications for implementation and evaluative research. Research of assessment which is done to students typically asks, "what works", whereas assessment that is done with the students focuses on more complex questions such as "what works, for whom, in which context, and why?" We applied such a critical realist perspective drawing on the interplay between structure and agency, and a systems approach to explore what theory says about introducing programmatic assessment in the context of pre-existing traditional approaches. Using a reflective technique, the internal conversation, we developed four factors that can assist educators considering major change to assessment practice in their own contexts. These include enabling positive learner agency and engagement; establishing argument-based validity frameworks; designing purposeful and eclectic evidence-based assessment tasks; and developing a shared narrative that promotes reflexivity in appreciating the complex relationships between assessment and learning. [ABSTRACT FROM AUTHOR]

Chromatin organization is a highly orchestrated process that influences gene expression, in part by modulating access of regulatory factors to DNA and nucleosomes. Here, we report that the chromatin accessibility regulator HMGN1, a target of recurrent DNA copy gains in leukemia, controls myeloid differentiation. HMGN1 amplification is associated with increased accessibility, expression, and histone H3K27 acetylation of loci important for hematopoietic stem cells (HSCs) and leukemia, such as HoxA cluster genes. In vivo, HMGN1 overexpression is linked to decreased quiescence and increased HSC activity in bone marrow transplantation. HMGN1 overexpression also cooperates with the AML-ETO9a fusion oncoprotein to impair myeloid differentiation and enhance leukemia stem cell (LSC) activity. Inhibition of histone acetyltransferases CBP/p300 relieves the HMGN1-associated differentiation block. These data nominate factors that modulate chromatin accessibility as regulators of HSCs and LSCs, and suggest that targeting HMGN1 or its downstream effects on histone acetylation could be therapeutically active in AML. Chromatin accessibility is a key mediator of gene expression and mutations in chromatin modifiers are frequently seen in cancers. Here, the authors show that the chromatin accessibility regulator HMGN1 - which is frequently mutated by amplification in leukemias - acts by blocking myeloid differentiation. [ABSTRACT FROM AUTHOR]

Profound metabolic changes are characteristic of macrophages during classical activation and have been implicated in this phenotype. Here we demonstrate that nitric oxide (NO) produced by murine macrophages is responsible for TCA cycle alterations and citrate accumulation associated with polarization. 13C tracing and mitochondrial respiration experiments map NO-mediated suppression of metabolism to mitochondrial aconitase (ACO2). Moreover, we find that inflammatory macrophages reroute pyruvate away from pyruvate dehydrogenase (PDH) in an NO-dependent and hypoxia-inducible factor 1α (Hif1α)-independent manner, thereby promoting glutamine-based anaplerosis. Ultimately, NO accumulation leads to suppression and loss of mitochondrial electron transport chain (ETC) complexes. Our data reveal that macrophages metabolic rewiring, in vitro and in vivo, is dependent on NO targeting specific pathways, resulting in reduced production of inflammatory mediators. Our findings require modification to current models of macrophage biology and demonstrate that reprogramming of metabolism should be considered a result rather than a mediator of inflammatory polarization. Production of inflammatory mediators by M1-polarized macrophages is thought to rely on suppression of mitochondrial metabolism in favor of glycolysis. Refining this concept, here the authors define metabolic targets of nitric oxide as responsible for the mitochondrial rewiring resulting from polarization. [ABSTRACT FROM AUTHOR]

Background: Previous studies suggested that the metabolism is differently reprogrammed in the major subtypes of non-small cell lung cancer (NSCLC), squamous cell carcinomas (SCC) and adenocarcinomas (AdC). However, a comprehensive analysis of this differential metabolic reprogramming is lacking.Methods: Publicly available gene expression data from human lung cancer samples and cell lines were analysed. Stable isotope resolved metabolomics were performed on SCC and ADC tumours in human patients and in freshly resected tumour slices.Results: Analysis of multiple transcriptomics data from human samples identified a SCC-distinguishing enzyme gene signature. SCC tumours from patients infused with [U-13C]-glucose and SCC tissue slices incubated with stable isotope tracers demonstrated differential glucose and glutamine catabolism compared to AdCs or non-cancerous lung, confirming increased activity through pathways defined by the SCC metabolic gene signature. Furthermore, the upregulation of Notch target genes was a distinguishing feature of SCCs, which correlated with the metabolic signature. Notch and MYC-driven murine lung tumours recapitulated the SCC-distinguishing metabolic reprogramming. However, the differences between SCCs and AdCs disappear in established cell lines in 2D culture.Conclusions: Our data emphasise the importance of studying lung cancer metabolism in vivo. They also highlight potential targets for therapeutic intervention in SCC patients including differentially expressed enzymes that catalyse reactions in glycolysis, glutamine catabolism, serine, nucleotide and glutathione biosynthesis. [ABSTRACT FROM AUTHOR]

Purpose of Review: Engagement on social media for professional, healthcare-related communication is rapidly rising around the world. We aimed to better understand the dynamics of a rare disease Twitter hashtag community.Recent Findings: Twitter has served as a platform for academic discussion, a method for knowledge dissemination directly from medical meetings, and a venue for patient caregiver and support groups. One example of a rare cancer that has seen an increase in available information via Twitter is blastic plasmacytoid dendritic cell neoplasm, or BPDCN. This field has recently experienced a new wave of interest from various healthcare stakeholders in light of key new scientific breakthroughs and novel clinical trials now starting to be available.Summary: In order to bring all relevant healthcare stakeholders together, the investigators of this article created a disease-specific Twitter community: #BPDCN = "blastic plasmacytoid dendritic cell neoplasm on social media" which has led to higher levels of engagement and discussion in the field. This article focuses on our analysis of advanced Twitter user-metrics in the second year of #BPDCN and discusses future directions for this rare cancer online disease community. [ABSTRACT FROM AUTHOR]

Purpose of Review: The use of Twitter, one of the most commonly engaged social media platforms in the world, is increasing among the general public. Notably, this trend has also been observed among those involved in the healthcare field. With its ability to readily connect diverse groups of stakeholders in a given area of interest, Twitter has become a focal point for those involved in increasing awareness and information exchange in orphan disease fields. Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive hematologic malignancy with generally poor long-term outcomes for adult patients and no standard therapeutic guidelines. Coupled with its low incidence rate, the disease has experienced a number of name changes over the past three decades (e.g., blastic NK cell lymphoma, CD4+CD56+ hematodermic tumor), thereby historically resulting in difficulties in its clinico-pathologic diagnosis and treatment approaches. All of these factors have led to a striking gap in terms of accurate information available to patients and the general public. Therefore, there is an urgent need for the development of more venues for the dissemination of information, particularly online, for this rare cancer. Recent Findings: In this context, we began the Twitter medical community, #BPDCN, over a year ago, to help fill this information void. Summary: Now, completing its first year of existence, we aimed to analyze the metrics of Twitter use in order to better understand and to describe the characteristics and reach in of #BPDCN, and to determine the feasibility of starting and maintaining a disease-specific hashtag community in a particularly rare cancer. [ABSTRACT FROM AUTHOR]

Delivering isotopic tracers for metabolic studies in rodents without overt stress is challenging. Current methods achieve low label enrichment in proteins and lipids. Here, we report noninvasive introduction of 13C6-glucose via a stress-free, ad libitum liquid diet. Using NMR and ion chromatography-mass spectrometry, we quantify extensive 13C enrichment in products of glycolysis, the Krebs cycle, the pentose phosphate pathway, nucleobases, UDP-sugars, glycogen, lipids, and proteins in mouse tissues during 12 to 48 h of 13C6-glucose feeding. Applying this approach to patient-derived lung tumor xenografts (PDTX), we show that the liver supplies glucose-derived Gln via the blood to the PDTX to fuel Glu and glutathione synthesis while gluconeogenesis occurs in the PDTX. Comparison of PDTX with ex vivo tumor cultures and arsenic-transformed lung cells versus xenografts reveals differential glucose metabolism that could reflect distinct tumor microenvironment. We further found differences in glucose metabolism between the primary PDTX and distant lymph node metastases. [ABSTRACT FROM AUTHOR]

The incorporation of Internet resources and the use of social media among patients, clinicians, advocates, and researchers in the field of hematology and oncology are growing in importance. Utilization of online information sharing is rising, especially among those involved in rare blood cancer fields, which have generally featured a paucity of reliable, updated information. In particular, blastic plasmacytoid dendritic cell neoplasm (BPDCN), an uncommon, but highly aggressive hematologic malignancy, is one example of a cancer with limited information readily available to the general public. The infrequent incidence of BPDCN, the challenges in recognizing the disease and making a clinico-pathologic diagnosis, and the lack of standard therapies are some of the reasons accounting for the dearth of expert opinion, scientific publications and discussion, and accessibility of online information for patients. This article highlights social media and Internet sources available for patients and other healthcare stakeholders in the field of BPDCN and discusses our efforts to increase awareness and propagation of BPDCN electronic resources, including the founding of an online Twitter community, #BPDCN. [ABSTRACT FROM AUTHOR]

Mitochondrial malic enzyme 2 (ME2) catalyzes the oxidative decarboxylation of malate to yield CO2 and pyruvate, with concomitant reduction of dinucleotide cofactor NAD+ or NADP+. We find that ME2 is highly expressed in many solid tumors. In the A549 non-small cell lung cancer (NSCLC) cell line, ME2 depletion inhibits cell proliferation and induces cell death and differentiation, accompanied by increased reactive oxygen species (ROS) and NADP+/NADPH ratio, a drop in ATP, and increased sensitivity to cisplatin. ME2 knockdown impacts phosphoinositide-dependent protein kinase 1 (PDK1) and phosphatase and tensin homolog (PTEN) expression, leading to AKT inhibition. Depletion of ME2 leads to malate accumulation and pyruvate decrease, and exogenous cell permeable dimethyl-malate (DMM) mimics the ME2 knockdown phenotype. Both ME2 knockdown and DMM treatment reduce A549 cell growth in vivo. Collectively, our data suggest that ME2 is a potential target for cancer therapy. [ABSTRACT FROM AUTHOR]

Down syndrome confers a 20-fold increased risk of B cell acute lymphoblastic leukemia (B-ALL), and polysomy 21 is the most frequent somatic aneuploidy among all B-ALLs. Yet the mechanistic links between chromosome 21 triplication and B-ALL remain undefined. Here we show that germline triplication of only 31 genes orthologous to human chromosome 21q22 confers mouse progenitor B cell self renewal in vitro, maturation defects in vivo and B-ALL with either the BCR-ABL fusion protein or CRLF2 with activated JAK2. Chromosome 21q22 triplication suppresses histone H3 Lys27 trimethylation (H3K27me3) in progenitor B cells and B-ALLs, and 'bivalent' genes with both H3K27me3 and H3K4me3 at their promoters in wild-type progenitor B cells are preferentially overexpressed in triplicated cells. Human B-ALLs with polysomy 21 are distinguished by their overexpression of genes marked with H3K27me3 in multiple cell types. Overexpression of HMGN1, a nucleosome remodeling protein encoded on chromosome 21q22 (refs. 3,4,5), suppresses H3K27me3 and promotes both B cell proliferation in vitro and B-ALL in vivo. [ABSTRACT FROM AUTHOR]

The study investigated responses to false feedback in laboratory cycling. Seven male competitive cyclists (age; M = 34.14 years, SD = 7.40) completed two ergometer time-trials, one each with false negative and false positive feedback (time ± 5 %). MANOVA indicated main effects for condition [ F(17, 104) = 9.42, p < 0.001], and mile [ F(153, 849) = 1.58, p < 0.001], but no interaction [ F(153, 849) = 0.470, p = 1.00]. No between-condition differences in power ( F = 0.129, p = 0.720) or time to completion ( F = 1.011, p = 0.338) were observed. Positive feedback was associated with higher glucose ( F = 25.988, p < 0.01), happiness ( F = 6.097, p = 0.015) and calmness ( F = 4.088, p = 0.045). Positive feedback was also associate with lower oxygen uptake ( F = 8.830, p = 0.004), anxiety ( F = 5.207, p = 0.024), gloominess ( F = 6.322, p = 0.013), sluggishness ( F = 11.650, p = 0.001), downheartedness ( F = 15.844, p = 0.001), effort required to regulate emotion ( F = 13.798, p = 0.001), and a trend towards lower lactate production ( F = 3.815, p = 0.053). Data suggest that positive emotions and reduced metabolic cost of performance were associated with positive feedback. [ABSTRACT FROM AUTHOR]

Fourier transform-ion cyclotron resonance-mass spectrometry (FTICR-MS) is capable of acquiring unmatched quality of isotopologue data for stable isotope resolved metabolomics (SIRM). This capability drives the need for a continuous ion introduction for obtaining optimal isotope ratios. Here we report the simultaneous analysis of mono and dinucleotides from crude polar extracts by FTICR-MS by adapting an ion-pairing sample preparation method for LC-MS analysis. This involves a rapid cleanup of extracted nucleotides on pipet tips containing a C stationary phase, which enabled global analysis of nucleotides and their C isotopologues at nanomolar concentrations by direct infusion nanoelectrospray FTICR-MS with 5 min of data acquisition. The resolution and mass accuracy enabled computer-assisted unambiguous assignment of most nucleotide species, including all phosphorylated forms of the adenine, guanine, uracil and cytosine nucleotides, NAD, NADH, NADP, NADPH, cyclic nucleotides, several UDP-hexoses, and all their C isotopologues. The method was applied to a SIRM study on human lung adenocarcinoma A549 cells grown in [U-C] glucose with or without the anti-cancer agent methylseleninic acid. At m/z resolving power of 400,000, C-isotopologues of nucleotides were fully resolved from all other elemental isotopologues, thus allowing their C fractional enrichment to be accurately determined. The method achieves both high sample and high information throughput analysis of nucleotides for metabolic pathway reconstruction in SIRM investigations. [ABSTRACT FROM AUTHOR]

We have developed a simple NMR-based method to determine the turnover of nucleotides and incorporation into RNA by stable isotope resolved metabolomics (SIRM) in A549 lung cancer cells. This method requires no chemical degradation of the nucleotides or chromatography. During cell growth, the free ribonucleotide pool is rapidly replaced by de novo synthesized nucleotides. Using [U-C]-glucose and [U-C,N]-glutamine as tracers, we showed that virtually all of the carbons in the nucleotide riboses were derived from glucose, whereas glutamine was preferentially utilized over glucose for pyrimidine ring biosynthesis, via the synthesis of Asp through the Krebs cycle. Incorporation of the glutamine amido nitrogen into the N3 and N9 positions of the purine rings was also demonstrated by proton-detected N NMR. The incorporation of C from glucose into total RNA was measured and shown to be a major sink for the nucleotides during cell proliferation. This method was applied to determine the metabolic action of an anti-cancer selenium agent (methylseleninic acid or MSA) on A549 cells. We found that MSA inhibited nucleotide turnover and incorporation into RNA, implicating an important role of nucleotide metabolism in the toxic action of MSA on cancer cells. [ABSTRACT FROM AUTHOR]

We proposed that experiencing unpleasant emotions during performance represents unsuccessful emotion-regulatory efforts, and that such effort concurrently tax physiological resources. We used data from 2-h cycling trials (N = 28) at a power output equivalent to lactate threshold. Emotions were calculated before and during cycling with ongoing assessments of ventilation, respiratory quotient, heart rate, and oxygen uptake. Emotion data indicated significant changes over time with all participants reporting decreases in vigour and increases in fatigue, with 14 cases of concurrent increases in anger, depression, and tension. After grouping participants into positive and negative emotion groups, a time x unpleasant emotion group ANOVA indicated a significant interaction effect for changes in ventilation ( F = 3.09, P = .03, Partial Eta = .47) over time, with no significant difference in other physiological variables or perceived exertion. Among athletes reporting negative emotions, ventilation increased during the middle section, whereas among athletes reporting positive emotions, ventilation increased shortly before completion. Findings suggest that regulating negative emotion is an effortful process taxing physiological substrates. [ABSTRACT FROM AUTHOR]

We have determined the time course of [U-C]-glucose utilization and transformations in SCID mice via bolus injection of the tracer in the tail vein. Incorporation of C into metabolites extracted from mouse blood plasma and several tissues (lung, heart, brain, liver, kidney, and skeletal muscle) were profiled by NMR and GC-MS, which helped ascertain optimal sampling times for different target tissues. We found that the time for overall optimal C incorporation into tissue was 15-20 min but with substantial differences in C labeling patterns of various organs that reflected their specific metabolism. Using this stable isotope resolved metabolomics (SIRM) approach, we have compared the C metabolite profile of the lungs in the same mouse with or without an orthotopic lung tumor xenograft established from human PC14PE6 lung adenocarcinoma cells. The C metabolite profile shows considerable differences in [U-C]-glucose transformations between the two lung tissues, demonstrating the feasibility of applying SIRM to investigate metabolic networks of human cancer xenograft in the mouse model. [ABSTRACT FROM AUTHOR]

Chronic rhinosinusitis (CRS) is a prevalent health condition characterized by sinonasal mucosal inflammation lasting at least 12 weeks. Heterogeneous in clinical presentation, histopathology, and therapeutic response, CRS represents a spectrum of disease entities with variable pathophysiology. Increased knowledge of cellular and molecular derangements in CRS suggests potential etiologies and targets for therapy. Microbial elements including fungi, staphylococcal enterotoxin, and biofilms have been implicated as inflammatory stimuli, along with airborne irritants and allergens. Defects in innate immunity have gained increased attention as contributors to the chronic inflammatory state. A combination of host susceptibility and environmental exposure is widely believed to underlie CRS, although direct evidence is lacking. Presently, without precise disease definitions and identifiable universal triggers, CRS pathogenesis is broadly described as multifactorial. Current research is beginning to unravel complex and diverse effects of chronic inflammation on sinonasal mucosal homeostasis, but dysfunctional pathways of inflammatory regulation and resolution require further elucidation. [ABSTRACT FROM AUTHOR]

n important goal of metabolomics is to characterize the changes in metabolic networks in cells or various tissues of an organism in response to external perturbations or pathologies. The profiling of metabolites and their steady state concentrations does not directly provide information regarding the architecture and fluxes through metabolic networks. This requires tracer approaches. NMR is especially powerful as it can be used not only to identify and quantify metabolites in an unfractionated mixture such as biofluids or crude cell/tissue extracts, but also determine the positional isotopomer distributions of metabolites derived from a precursor enriched in stable isotopes such as C and N via metabolic transformations. In this article we demonstrate the application of a variety of 2-D NMR editing experiments to define the positional isotopomers of compounds present in polar and non-polar extracts of human lung cancer cells grown in either [U-C]-glucose or [U-C,N]-glutamine as source tracers. The information provided by such experiments enabled unambiguous reconstruction of metabolic pathways, which is the foundation for further metabolic flux modeling. [ABSTRACT FROM AUTHOR]

Despite the long-established therapeutic efficacy of lithium in the treatment of bipolar disorder (BPD), its molecular mechanism of action remains elusive. Newly developed stable isotope-resolved metabolomics (SIRM) is a powerful approach that can be used to elucidate systematically how lithium impacts glial and neuronal metabolic pathways and activities, leading ultimately to deciphering its molecular mechanism of action. The effect of lithium on the metabolism of three different 13C-labeled precursors ([U-13C]-glucose, 13C-3-lactate or 13C-2,3-alanine) was analyzed in cultured rat astrocytes and neurons by nuclear magnetic resonance (NMR) spectroscopy and gas chromatography mass spectrometry (GC-MS). Using [U-13C]-glucose, lithium was shown to enhance glycolytic activity and part of the Krebs cycle activity in both astrocytes and neurons, particularly the anaplerotic pyruvate carboxylation (PC). The PC pathway was previously thought to be active in astrocytes but absent in neurons. Lithium also stimulated the extracellular release of 13C labeled-lactate, -alanine (Ala), -citrate, and -glutamine (Gln) by astrocytes. Interrogation of neuronal pathways using 13C-3-lactate or 13C-2,3-Ala as tracers indicated a high capacity of neurons to utilize lactate and Ala in the Krebs cycle, particularly in the production of labeled Asp and Glu via PC and normal cycle activity. Prolonged lithium treatment enhanced lactate metabolism via PC but inhibited lactate oxidation via the normal Krebs cycle in neurons. Such lithium modulation of glycolytic, PC and Krebs cycle activity in astrocytes and neurons as well as release of fuel substrates by astrocytes should help replenish Krebs cycle substrates for Glu synthesis while meeting neuronal demands for energy. Further investigations into the molecular regulation of these metabolic traits should provide new insights into the pathophysiology of mood disorders and early diagnostic markers, as well as new target(s) for effective therapies. [ABSTRACT FROM AUTHOR]

Chronic rhinosinusitis (CRS) is a heterogeneous inflammatory condition with a multifactorial basis. Infectious triggers of CRS have been proposed, but demonstration remains elusive. Evolving research suggests that abnormal host mucosal immune responses, rather than specific pathogens themselves, may underlie the chronic inflammatory state. Despite constant contact with airborne particulates and microorganisms, the sinonasal epithelium maintains mucosal homeostasis through innate and adaptive immune mechanisms that eliminate potential threats. Innate immunity encompasses a broad collection of constitutive and inducible processes that can be nonspecific or pathogen directed. Some innate immune pathways are closely intertwined with tissue growth and repair. The persistent inflammation observed in CRS may result from a pathologic imbalance in innate immune interactions between the host and the environment. Impairment of critical innate immune protection renders the sinonasal mucosal surface susceptible to colonization and potential injury, stimulating the prominent adaptive immune response that characterizes CRS. [ABSTRACT FROM AUTHOR]

Soil microorganisms are the primary mediators of organic matter decomposition and humification processes in soil, which represent a critical C flux in the global C cycle. Little is known about how soil microbes regulate carbon cycling including the contribution of their own biomass to stable soil organic matter. A comprehensive understanding of microbial composition is a first step to unraveling microbial regulation of soil humification processes. For this purpose, we isolated 23 microbial strains representing four major groups (Gram (+) bacteria, Gram (−) bacteria, Actinobacteria, and Fungi) from a temperate and a tropical forest soil. The microbial isolates were cultured with uniformly 13C-labeled glucose as the C source such that all biochemical components synthesized from glucose were 13C labeled. This approach enabled field mesocosm experiments on tracking microbial decomposition, while facilitating solution- and solid-state NMR analysis of microbial composition. Polar and lipid extracts of labeled biomass of the four microbial groups from the two forest sites were profiled by 2D NMR methods, including high-resolution heteronuclear single quantum coherence spectroscopy and HCCH-total correlation spectroscopy. This 13C labeling approach also enabled the analysis of intact biomass by 2D solid-state 13C–13C correlation spectroscopy. Distinction between microbial groups and sites was observed in the polar and lipophilic metabolite profiles. Dominant differences could also be related to the capacity for lipid β-oxidation or adaptation to desiccation. Solid-state NMR further revealed differential synthetic capacity for glycolipids among groups. This technology coupled with 13C metabolite profiling should facilitate future functional annotation of indigenous microbial genomes. [ABSTRACT FROM AUTHOR]

Isotopomer analysis is a very powerful technique for determining site enrichment with stable isotopes. Such information helps determine the relative flux through metabolic pathways. We have developed 1H NMR detection methods to isotopomer analysis of human rhabdomyosarcoma cells grown in the presence of uniformly 13C-labeled glucose. We show that TOCSY can be used both to identify the isotopomer distributions in a substantial number of key compounds and to determine the site-specific enrichment with good precision. Effects of differential relaxation have been specifically addressed. We have identified and quantified isotopomer distributions in Ala, Lactate, (glycolysis markers), nucleotide riboses (pentose phosphate markers), Asp, Glu and Gln (citric acid cycle and anaplerosis markers) as well as in nucleotide pyrimidine rings. Due to the high sensitivity of proton experiments, a reasonable throughput was achieved using a cold probe on only 3–5 mg dry cell weight. This methodology can be applied to biological system using different labeled precursors to examine their metabolic phenotypes and their response to external perturbations. [ABSTRACT FROM AUTHOR]

The present study examined changes in primary and secondary appraisal, and coping strategies utilized in the final weeks leading to dissertation submission. Sixty volunteer Sports Studies dissertation students (male: n = 29; female: n = 31) completed an adapted Cognitive Appraisal of Health Scale (CAHS: Kessler, 1998), and Brief COPE (Carver, Scheier, & Weintraub, 1989) on 4 occasions over the 6 weeks before dissertation submission. Repeated measures multivariate analysis of variance indicated a significant main effect for gender, with no main effect for changes over time and no significant interaction effect. Results demonstrated that males perceived the dissertation to be significantly more threatening and less challenging than females. With regard to coping, males used more active coping, positive reframing, planning, and acceptance of the stressor, with lower scores for self-blame, venting of emotions, and behavioral disengagement. The results suggest that, for this student population, the dissertation did not become increasingly stressful in the period before submission. Clear relationships were also evidenced between primary appraisal, secondary appraisal, and coping. Future research should seek to identity factors that moderate the influence of situational stressors on coping responses among undergraduate students. [ABSTRACT FROM AUTHOR]

The development and application of a Lagrangian particle-tracking model to simulate sediment transport in the Mersey Estuary (UK) is described. Each of the particles (up to a million in total) is advected horizontally by the 3-D tidal currents. Related vertical movements are: (1) downwards by settlement at a prescribed velocity w s and (2) both upwards and downwards by a distance related to the vertical eddy diffusivity. In a novel departure from traditional practice, where initial distributions of surficial sediments are specified, all particles are introduced at the seaward boundary of the model. Provenance studies indicate surficial sediments are overwhelmingly of marine origin. For the predominant fine sediments, ‘cyclical convergence’ in suspended sediment concentrations is approximated after about two spring-neap tidal cycles. Comparisons are shown between the suspended sediment concentrations and net deposition rates computed by this model against observed values and earlier computations utilising both 1-D and 3-D Eulerian models. While all of these results are in broad agreement, the flexibility of the Lagrangian approach for simulating flocculation, consolidation and mixed sediments illustrates its future potential. [ABSTRACT FROM AUTHOR]

Transcriptomic analysis is an essential tool for systems biology but it has been stymied by a lack of global understanding of genomic functions, resulting in the inability to link functionally disparate gene expression events. Using the anticancer agent selenite and human lung cancer A549 cells as a model system, we demonstrate that these difficulties can be overcome by a progressive approach which harnesses the emerging power of metabolomics for transcriptomic analysis. We have named the approach Metabolomics-edited transcriptomic analysis (META). The main analytical engine was C isotopomer profiling using a combination of multi-nuclear 2-D NMR and GC-MS techniques. Using C-glucose as a tracer, multiple disruptions to the central metabolic network in A549 cells induced by selenite were defined. META was then achieved by coupling the metabolic dysfunctions to altered gene expression profiles to: (1) provide new insights into the regulatory network underlying the metabolic dysfunctions; (2) enable the assembly of disparate gene expression events into functional pathways that was not feasible by transcriptomic analysis alone. This was illustrated in particular by the connection of mitochondrial dysfunctions to perturbed lipid metabolism via the AMP-AMPK pathway. Thus, META generated both extensive and highly specific working hypotheses for further validation, thereby accelerating the resolution of complex biological problems such as the anticancer mechanism of selenite. [ABSTRACT FROM AUTHOR]

Cross-saturation experiments have been shown to give accurate information regarding the interacting surfaces in protein-protein and protein-RNA complexes. The rate of magnetization transfer depends on a number of factors including geometry, spin topology, and effective correlation times. To assess the influence of these variables on such experiments, and to determine the range of applicability of the technique, we have simulated the time-course of magnetization transfer across the interface in a variety of protein-nucleic acid complexes (434 Cro, SRY, MetJ and U1A), each having a different binding geometry. The simulations have been carried out primarily to provide information about the experimentally accessible targets for selective saturation, such as the anomeric protons and the imino protons of the nucleic acid. Saturation of either of these groups of signals leads to partial excitation throughout the nucleic acid molecule, and the resulting transfer of saturation to the labelled protein moiety can be readily detected by the reduction in intensity of particular peaks in the HSQC spectrum of the protein. The simulations show that information can be obtained about the residues in contact with the nucleic acid without any need for deuteration. Experimental cross-saturation data have been obtained from the Mbp1-DNA complex and interpreted in conjunction with the simulations to map out the binding surface in detail. [ABSTRACT FROM AUTHOR]

Reports on the detection of ultrasensitive pheromones by vomeronasal neurons. Function of the vomeronasal organ (VNO), which is thought to transduce the pheromones into electrical responses; Use of a mouse VNO slice preparation to demonstrate the theory; Results from the research collected.

Mbp1 is a transcription factor involved in the regulation of the cell cycle in yeast. The N-terminus of this protein contains a DNA binding domain that includes a winged helix-turn-helix motif. The C-terminal 24 residues of this domain (the `tail') are disordered in the crystal state, but are important for DNA binding. We have measured 15N NMR relaxation rates at 11.75 and 14.1 T to determine the dynamics of the free protein and in its complex with a specific DNA duplex. The dynamics data were quantitatively analysed using both spectral density mapping and the Lipari–Szabo formalism including the effects of chemical exchange and rotational anisotropy. A detailed analysis has been made of the effect of anisotropy, exchange and experimental precision on the recovered motional parameters. The backbone NH relaxation is affected by motions on a variety of time scales from millisecond to tens of picoseconds. The relaxation data show a structured core of 100 residues corresponding to that observed in the crystal state. Within the core of the protein, two regions on either side of the putative recognition helix (helix B) show slow (ca. 0.2 ms) conformational exchange dynamics that are quenched upon DNA binding. The C-terminal 24 residues are generally more dynamic than in the core. However, in the free protein, a stretch of ∼8 residues in the middle of the tail show relaxation behaviour similar to that in the core, indicating a structured region. NOEs between Ala 114 in this structured part of the tail and residues in the N-terminal beta strand of the core of the protein demonstrate that the tail folds back onto the core of the protein. In the complex with DNA, the structured part of the tail extends by ca. 3 residues. These data provide a framework for understanding the biochemical data on the mechanism and specificity of DNA binding. [ABSTRACT FROM AUTHOR]

The majority of the H NMR resonances of the protons in a tetradecamer containing the -35 region of the trp promoter d(GCTGTTGACAATTA): d(TAATTGTCAACAGC) and in the TA transversion have been assigned. The conformational properties of the nucleotides have been determined and compared in the two duplexes. Analysis of spin-spin coupling and NOES shows that all sugar puckers are in the south domain (i.e. near C2′ endo) and the glycosidic torsion angles are anti (χ≈110°). The NMR data are consistent with the duplex being in the B family of conformations. Significant differences in chemical shifts between the two molecules were observed only for nearest neighbours to the transversion site, suggesting the absence of long range conformational effects. This was confirmed by the similarity of coupling constants and NOEs. Other properties are also not greatly affected at positions more than two base pairs from the mutation site. These results are consistent with the hypothesis that unconstrained oligonucleotides are highly flexible, and can readily accommodate significant perturbations of the local structure, such as a transversion. [ABSTRACT FROM AUTHOR]

The interaction of the trp repressor with several trp operator DNA fragments has been examined by DNA gel retardation assays and by circular dichroism, in the absence and presence of the corepressor l-tryptophan. The holorepressor binds stoichiometrically to both the trpO and aroH operators, forming 1:1 complexes. In the presence of excess protein, additional complexes are formed with these operator fragments. The relative electrophoretic mobilities of the 1:1 complexes differ significantly for trp and aroH operators, indicating that they differ substantially in gross structure. A mutant trp operator, trpO, has low affinity for the holorepressor, and forms only complexes with stoichiometries of 2:1 (repressor: DNA) or higher, which have a very low electrophoretic mobility. Specific binding is also accompanied by a large increase in the intensity of the near ultraviolet circular dichroism, with only a small blue shift, which is consistent with significant changes in the conformation of the DNA. Large changes in the chemical shifts of three resonances in the P NMR spectrum of both the trp operator and the aroH operator occur on adding repressor only in the presence of L-tryptophan, consistent with localised changes in the backbone conformation of the DNA. [ABSTRACT FROM AUTHOR]